Ball-caster



T, KELLY. BALL CASTER.

APPLICATION FILEDAPR-Z, I920. 1

1,375,394. Patented A r.- 19, 1921 1 7 3 ER v 6 2 4 INVENTOR Tkamas K6WITNESSES warren stares EFEQE THOMAS KELLY, 0F POULTON-W'ALLASEY,ENGLAND.

BALL-CASHIER.

Application filed April 2, 1920. Serial No. 370,776.

To all whom it may concern:

Be it known that I, THOMAS KELLY, a subkect of the King of GreatBritain, residing at oulton-Wallasey, in the county of Cheshire, Kingdomof England, have invented a new and useful Ball-(Jaster, of which thefollowing is a specification.

his invention relates to ball casters.

The object is to provide a caster of the ball-bearing type whichsupports the entire load of a piece of furniture or other article uponwhich the device may be used, through the medium of a single relativelylarge, ball contacting with the floor or other surface and freelyrotatable in any direction, the said ball being confined in a rotatablecage carrying a series of small balls interposed between the same andthe stationary ball race carried by the article of furniture.

Another object is to provide a device of this character which, whenmanufactured in quantities, may be produced at a low cost and, by reasonof the simplicity of its construction, may be readily applied to the-legof the furniture or other article, without weakening or detracting fromthe appearance of the same, and which will reduce to a minimum theliability of breakage or derangement while under the great strain towhich such devices are subjected. A full and complete understanding ofthe invention may be obtained from a consideration of the followingdetailed description taken in connection with the accompanying drawingforming part of this specification, with the understanding, however,that the invention is not confined to any strict conformity with theshowing of the drawing, but may be changed and modified so long as suchchanges or modifications mark no material departure from the salientfeatures of the invention as expressed in the appended claims. 7

In the drawing, in which similar reference characters designatecorresponding parts throughout the several figures- Figure 1 is a sideelevation of the lower portion of the leg of an article of furniturehaving the improved ball caster applied thereto;

Fig. 2 is a vertical sectional view of the same;

I Fig. 3 is an inverted plan view of the de- Fig. 4 is an inverted planview of the ball race member;

Fig. 5 is an inverted plan view of the ball ca e member.

eferrin to the drawing, there is illustrated in F gs. 1 and 2 the lowerportion of a leg 1, WlllCll may be that of any article of furniture,though the deviceis equally well adapted for use in any location whereit is desired to reduce to a minimum the friction between two relativelymovable bodies. At the lower end of said leg, which is shown as beinground in cross section, there is secured a hardmetal ball race or trackmember 2, which is also round and preferably of the same diameter astheleg 1, though this of course is not Obligatory. The ball race or track 2comprises a flat disk or plate 3 surrounded by a marginal, dependingflange 4, and having at its center, a straight bore or passageway 5 anda series of bores or passageways 6 arranged around the same, equid stanttherefrom and spaced an-equal distance apart. The latter bores arecountersunk on the inner face of the disk or plate 3 for the receptionof relatively short screws 7 which are driven into the lower end of theleg 1 and serve to securely hold the ball race or track member inposition thereon.

A rotatableball cage member 8, cylindri- V cal in form and of a diameterto fit freely within the depending flange 4, is also formed of steel orother hard metal, and comprises an upper disk or plate 9, flat upon itsupper surface and beveled underneath being considerably thinner at thecenter than at the periphery thereof, the center having a countersunkbore or passageway 10. The disk or plate 9 is provided with an integral,marglnal, depending flange l1, considerably longer than the aforesaidflange 4 of the ball race member, said flange being provided with anannular groove 12 upon the inner wall thereof and near the bottom end ofthe same,thus providing a hollow-cup-like ball cage member closed at thetop and open at the bottom and adapted to partially surround and house arelatively large steel ball 13 which is confined within the surroundinflange 11 and extends considerablyv below the lower edge thereof to restupon the floor or other supporting surface' The disk or plate 9 of theball cage member is provided with a series of hemi-spherical ball seats14, preferably three in number arranged equi-distantly from the centralbore or passageway 10 and an equal distance apart, as clearly shown inFig. 5 of the V i in spaced relation to the apex thereof and drawing,the said hemi-spherical ball seats extending through the disk or plate 9and each adapted to receive a steel ball 15 of considerably lessdiameter than the steel ball 13. Said balls 15 rest upon the larger ballproject through the seats 1 1 su'liiciently to bear upwardly against thelowerface of the ball race plateor. disk 3, and to transmit the weightcarried thereby directly upon the large ball with the minimum amount offriction, the three-point bearing thus provided, permitting of thegreatest amount of freedom of the ball 13 and allowing'the articlesupported by the caster to be moved in any desired direction with thegreatest ease. "Asplit ring 16 is adapted to be sprung i into the seat12 ofthe flange 11 and to retain i the ball 13 in its housing, the saidring lying when the same may be forced into the seat 12,'whereupon thering will expand and cocupythesame. It is only necessary in removing thesame, to introduce a pointed implement between the ends 17 of the ringand pry one of thejends out-of the 1 groove 12, when the entire ring 16may be removed, as will be clearly understood, by reference to "Fig. 3ofthe drawing.-

Inassemblingthe ball bearing caster, the

ball-race or trackmember 2 is first applied to the lower end of the leg1 by the applica- 40 V i securely hold the'member 2 in position, when{the cage member 8 is then introduced within tion of the relativelyshort screws 7, which the flange 4:, and a "somewhat longer screw 18 isscrewed through the alined passageways 5 and 10 respectively, and intothe center of l the leg along the longitudinal. axis thereof, the headof the long screw being embedded in the countersunk bore 10 and lyingflush with the underface of the plate or disk9. Thesmaller balls 15 arethen placed in their seats 1 1 and held therein by the larger ball "13which is next positioned within the annular flange 11, the ring 16 beingplaced in the groove last to retain the parts in their proper positibn.V a

It will be noted that the ball 13 is free to rotate in any direction,the smaller balls 15 being so positioned as to take up an equal 7 amountof the weight imposed thereon.

Vl hen the leg 1 is moved laterally the ball 7 13will impinge againstthe inner wall of the flange 11 and, under certain conditions, willcause the latter to rotate upon its vertical axis, the longer screw 18being screwed into the leg 1 in such manneras to permit of the ball cage8 rotating freely thereon, which overcomes any friction which mightarise if the flange 11 were not free to thus move.

From the foregoing it will be seen that a strong durable and eflicientanti-friction device has been provided for use upon the legs offurniture or for analogous purposes and that the same, by reason of thesimplicity of its construction, may be cheaply manufactured, readilyassembled and applied in position to give the maximum amount of delicacyorsensitiveness in its movement'and that the same is-calculated tosupport great weight and withstand strain, with the danger ofderangement or breakage reduced to a minimum. Y i i What is claimed isi 1. A ball bearing oaster comprising an upper or ball race membercomprising a flat disk or plate having a depending marginal flange, aball cage member having its upper portion fitted withinsaid flange andcomprising a flat disk or plate and a depending marginalflange, arelatively large ball arranged within the flange'of the cage member,means'for holding the ball therein, a series of small ballsrestinguponthe large ball at spaced points around the top thereof, and a plurality:of ball seats provided in the disk of the cage member, said seatsopening out at the top, whereby the small balls are adapted tocontact'with the roll against the 'upper member;

2. A'ball bearing caster including a ball race member comprising laplate or disk with a depending marginal'flange, a ball cage memberfitted within said flange, means for pi'votally mounting said ball cagemember in position so that it may rotate within" said flange, said ballcage member carrying a large ball, anda plurality of small ballsinterposed between said large ball and the ball cage member;

8'. A ballbearing caster comprising a ballrace member adapted tobesecured to the article to be supported and provided with'a dependingmarginal flange, a ball oage-me'mberfltting within said flange, saidcage member comprising a flat disk provided with spaced hemisphericalball seats which open out through the top,'relativ'ely small ballsfitting in said seats and projectingthrough I the same to bear againstthe ball race, a circular marginal flange depending from the r disk ofthe ball cage member, a relatively largeball arranged within thelast-named flange and bearing upwardly against the smaller balls wherebythe pressure is transmitted'to the ball race member, and means mountedon the depending marginal flange for holding. the large ball inposition;

4. A ball bearing caster comprising a ball race member adapted to besecured to the article to be supported'and provided with a dependingmarginal flange, a circular ball cage member fitting Within said flangeand held for rotation therein, said cage member comprising a disk flaton its upper face and provided with spaced hemispherical ball seatswhich open out through the top, relatively small balls fitting into theseats and projecting through the same to bear against the under side ofthe ball race, a circular marginal flange depending from the disk of theball cage member, the disk of the cage member being of least thicknessat its center, pivotal means passing through the center of the said diskfor holding the same to the ball race member, the disk of the cagemember being of greatest thickness Where it joins with the marginalflange, the small balls being seated intermediate the thinnest andthickest parts but equi-distant from'the pivot of the ball cage, arelatively large ball arranged Within the marginal flange of the cagemember and bearing upwardly against the smaller balls, and meanspreventing the large ball from dropping out of the cage member.

In testimon that I claim the foregoing as my own, nature.

THOMAS KELLY.

Witnesses WILLIAM PIERCE, JAMES CHARLES MORAE.

have hereto aflixed my sigi

